Secondary Source - Classification

Classification

Many sources can be considered either primary or secondary, depending on the context in which they are used. Moreover, the distinction between primary and secondary sources is subjective and contextual, so that precise definitions are difficult to make. For example, if a historical text discusses old documents to derive a new historical conclusion, it is considered to be a primary source for the new conclusion, but a secondary source of information found in the old documents. Other examples in which a source can be both primary and secondary include an obituary or a survey of several volumes of a journal counting the frequency of articles on a certain topic.

Whether a source is regarded as primary or secondary in a given context may change, depending upon the present state of knowledge within the field. For example, if a document refers to the contents of a previous but undiscovered letter, that document may be considered "primary", since it is the closest known thing to an original source, but if the letter is later found, it may then be considered "secondary".

Attempts to map or model scientific and scholarly communication need the concepts of primary, secondary and further "levels". One such model is the UNISIST model of information dissemination. Within such a model these concepts are defined in relation to each other, and the acceptance of this way of defining the concepts are connected to the acceptance of the model.

Some other modern languages use more than one word for the English word "source". German usually uses Sekundärliteratur ("secondary literature") for secondary sources for historical facts, leaving Sekundärquelle ("secondary source") to historiography. A Sekundärquelle is a source which can tell about a lost Primärquelle ("primary source"), such as a letter quoting from minutes which are no longer known to exist, so cannot be consulted by the historian.